For a science experiment you need to electroplate zinc onto both sides of a very thin, 1.00 {\rm cm} \times 1.00 {\rm cm} copper sheet. You want the zinc thickness to be 140 {\rm nm}, and you know that the charge carriers in the ionic solution are divalent (charge 2e) zinc ions. The density of zinc is 7140 kg/m^3.
If the electroplating apparatus operates at 1.40 {\rm mA}, how long will it take the zinc to reach the desired thickness?